Some containers for food products, such as cookies and other snacks, typically include an outer wrapper. In one type of container, the wrapper surrounds a frame which acts as a tray to hold the food product and to protect the food product from damage. Other food products come packaged in plastic trays, such as thermoform trays which are sealed on the top using some type of lid material or construction.
Reclosable seals or pressure-sensitive labels have been used for dispensing bags for wet tissue or disposable cleaning wipes. The label on these bags can be pulled back thereby exposing an opening, allowing access to the wet tissues or wipes inside. Typically, these dispensing bags are completely flexible, formed exclusively of a plastic or other suitable flexible material which closely surrounds the pack of wet tissues or wipes. Examples of these dispensing bags include U.S. Pat. Nos. 4,840,270 and 6,026,953; U.S. Design Pat. No. D447,054 and U.S. Patent Application Publication No. 2002/0182359. However, such known dispensing bags are not well suited for containing food products as these containers fail to provide adequate protection for storing food products. Other relatively pertinent recent advancements in the art of food container closures include resealable closures of the type disclosed in U.S. Pat. Nos. 6,918,532 and 8,114,451.
Containers for products such as sliced natural cheese or meat do not include a frame surrounded by an outer wrapper. The shingled slices of cheese or meat may be supported by a board underneath the stack of slices, but such boards are not always used. One normally gains access to the contents of the container by opening the side of the wrapper, withdrawing the entire stack of slices and then removing as many slices as desired from the stack. However, because opening and resealing these packages is accomplished with the use of tear tapes and press-to-close zippers along one side of the container, these containers generally require more packaging material than is necessary to package the food.
Typically these packages will have a notch on the end seal and a tear tape sealed within the package to facilitate opening the package along the entire length of the package. When one opens the package by initiating opening at the tear notch and propagates the tear using the tear tape, two flaps of film remain along the opening side for one to pull each flap apart from the other in order to disengage the press-to-close zipper and thus gain access to the food. Then, one slides the entire stack from the container, removes the desired portion of food from the stack and then slides the remaining contents back into the container, and then presses the zipper closed along its entire length.
In order to remove the entire stack of food from the container, the container must also be longer than is necessary to package the food because pulling the front and back panels of the package apart to open the container draws the ends of the package closer together. Without extra length to the container it would be impossible to remove the entire stack from the container. Additionally, re-engaging the press-to-close zipper requires manual dexterity that older users may lack; even those having the required dexterity are often fooled by a clicking sound into thinking the zipper has be closed when it has not. When the zipper is not properly closed, the contents of the package can dry out and spoil faster than expected.
In another aspect, containers for products such as cooked and sliced meat are packaged in thermoformed plastic trays with flexible plastic lidding. The lidding is typically sealed to the filled tray on a flat flange along the outside perimeter of the tray using a specific combination of heat, pressure and dwell time. In some instances the lidding may be welded to the tray such that access to the food is gained only by cutting through the lid, which renders the package not reclosable. In other instances, the lidding may be peelable only, making the package easy to open, but still not reclosable. In other instances, the lidding itself may be peelable and resealable, such that package is easy to open and easy to reseal, but since the reseal area is only the width of the heat seal on the flange of the tray, even a small amount of contamination in the seal area can render the package not resealable.
In another aspect, containers for products such as cooked and sliced meats are packaged in thermoformed plastic trays with flexible plastic lidding, that has been die-cut to create an opening flap and immediately labeled to prevent the flap from curling such that a pressure-sensitive label would not be effective in keeping the lidding closed to protect the contents of the package. Since in this aspect the lidding material must be cut through and labeled simultaneously, the cutting and labeling must be performed directly on the packaging machine just prior to the lidding being sealed to the thermoformed tray. This requires a special adaptation to the packaging equipment adding a station for cutting and labeling, thus increasing the complexity of the packaging operation for the food packager.
An alternative to cutting and labeling on the packaging machinery is cutting and labeling in advance of placing the roll of packaging material on the packaging machine. Although this will minimize the complexity during the packaging operation, the food packager must accept shorter footage on each roll of packaging material. Each packaging machine has a maximum roll diameter for packaging material and if the lidding material also includes the labels, the length of material on the roll may be reduced by fifty percent or more.
Short rolls of packaging materials results in more roll changes, reduced productivity, and higher waste. This type of reclosable package can also be adapted to wrappers around a frame or tray containing food such as described for the cookie packaging above or wrappers with without a tray such as described for the natural cheese slices package described above. All such packages that incorporate die-cutting and labeling to achieve easy opening and resealability shall be referred to in this specifications as “die-cut and labeled” packaging systems.
In this document, the present invention shall be referred to as “scored and labeled” packaging systems. Although the end consumer may perceive die-cut and labeled packages to function similarly to scored and labeled packages, there are important differences for the food packager. In the packaging art, different methods have been used to indicate whether a package has been previously opened or whether the integrity of the package has been compromised, which is often referred to in the art as “tamper-evident.” For example, in the tissue wipes packaging art of U.S. Pat. No. 6,428,867 (hereinafter “the '867 patent”), a means for indicating package integrity includes a tamper-evident tab with one or more ink layers which is initially an integral part of a sealing panel prior to the package being opened for a first time. The tab is transferred with one of the ink layers from the sealing panel to the top of the package when the closure has been opened for a first time. Tamper-evidence is indicated in a misalignment of the sealing panel with an image on the transferred tab, which is visible through a transparent outer layer of the sealing panel, after the sealing panel has been resealed to the top of the package.
There is a need for improvement in the art for package integrity indicators for a resealable closure, preferably suitable for use with a resealable closure for containers or packages containing food items.